Nuclear threats today

In the 1940s a group of atomic scientists designed the ‘Doomsday Clock’ to keep track of the likelihood of a nuclear war. The clock’s minute hand moves closer to midnight or further away
depending on the estimated risk of nuclear war.

In 1947, the minute hand stood at 7 minutes to midnight.

In 1953, as the Soviet Union increased testing of nuclear devices, it advanced to a state of imminent threat at 2 minutes to midnight

In 1991, after the superpowers agreed to reduce nuclear arms it was set back to 17 minutes to midnight, and the world breathed a sigh of relief

At the end of 2016 the clock was re-set to just 2.5 minutes to midnight – a near historical high for the risk of man-made annihilation. And in this evaluation the new tensions between the US and North Korea haven’t even been taken into consideration.

When countries are embroiled in a conflict that seems insoluble, or if they face defeat in a conventional war, the temptation to use nuclear weapons becomes greater. For this reason, any conventional war between nuclear powers risks escalating to nuclear war.Here are five possible scenarios in which nuclear arms could be deployed.

Scenario 1: Large-scale nuclear attack

A large-scale attack would involve nuclear missile hits on 250 US cities with a total yield of 7800 megatons. The result would be the loss of millions of human lives, accompanied by similarly catastrophic levels of injury, and the physical destruction of much American economic and industrial capacity.

Scenario 2: ‘Limited’ nuclear exchange

A nuclear detonation over the Indian city of Mumbai with a small 15 kiloton bomb would cause up to 866,000 deaths. A ‘limited’ nuclear exchange between India and Pakistan with 10 small nuclear weapons (15 kt each) exploding on the main cities in both countries would result in 2.6 million deaths in India and 1.8 million in Pakistan, with a further 1.5 million injured. These figures do not include the indirect health effects resulting from the destruction of the health service and urban infrastructure, or long-term effects such as cancers (Ramana 1999; Ramana et al. 2001).

Scenario 3: Attack on hardened underground target

The use of a robust nuclear earth penetrator, known as a ‘nuclear bunker buster’, against targets, hardened against attack by being buried and cased in concrete. In Iran or North Korea could cause millions of deaths, and lead to millions more acute and long-term health problems for civilians and military personnel. In one scenario – using the bunker buster against Isfahan, Iran – up to 20,000 US military personnel stationed in Afghanistan and 35 million civilians in Iran, Afghanistan, Pakistan and India could receive enough radiation to cause up to three million deaths.

Scenario 4: Accidental nuclear war

The US and Russia have an estimated 2000 nuclear weapons on high alert and an accidental nuclear exchange could be triggered by a false computer alarm. Because there can be no retaliation after a country has been hit, nuclear states have instituted a policy of ‘launch-on-warning’. There have been several false alarms in the past, which were fortunately averted by split-second human decision not to act on computer commands.

Scenario 5: ‘Unauthorized’ use

The use of nuclear weapons by unauthorized persons includes military personnel without proper authority, computer hackers and stolen nuclear weapons. There is also the problem of primitive nuclear weapons built by non-state actors (referred to as ‘terrorists’).

For more information and further reading, see the ‘See Also’ section below.